1. Field of the Invention
The present invention relates to a lens driving mechanism and an image capture apparatus that move a lens, which carries out a focusing operation and the like, in an optical axis direction, and more specifically a lens driving mechanism and an image capture apparatus that have a clearance in the driving mechanism if an error occurs in a movement control of a lens.
2. Description of Related Art
In recent years, improvement of portability and advancement of convenience are demanded for the image capture apparatuses, such as a digital still camera, a digital video camera and the like. Furthermore, reduction of the total apparatus size and sizes of an optical system barrel and lens used in the image capture apparatus are advanced. Further, demands for higher picture quality and more pixels are also strong. Accordingly, the miniaturization of the optical system barrel is desirable by reducing the size of the driving mechanism even if the lens that is a constituting element of the optical system is made larger.
Further, with regard to a so-called collapsible lens used in the image capture apparatus, such as a digital still camera, a digital video camera and the like, reduction in size and thickness are desirable in view of portability convenience as mentioned above. Specifically, there is a trend such that modern digital still camera having higher portability and convenience is more favored, since it can be put in a pocket of a shirt or a pocket of jeans and the like. Accordingly, for the optical system barrel, reduction in its thickness is highly desirable.
Such a collapsible lens and collapsible barrel are disclosed in Japanese Patent Application Publication JP 2002-296480, and the lens driving mechanism is disclosed in Japanese Patent Application Publication JP 2002-287002 and the like. In these techniques, a lead screw, a guiding axis, a nut and forcing element are used to constitute the lens driving mechanism. The movement of the nut through the rotation of the lead screw causes a lens holding frame to move in a direction of an optical axis.
[Patent Document 1]
Japanese Patent Application Publication JP 2002-296480
[Patent Document 2]
Japanese Patent Application Publication JP 2002-287002